java - Spring RedirectAttributes 导致 "Cannot create a session after the response has been committed"错误

Question

向 Flash map 添加重定向属性会导致以下异常

java.lang.IllegalStateException: Cannot create a session after the response has been committed
    at org.apache.catalina.connector.Request.doGetSession(Request.java:2377)
    at org.apache.catalina.connector.Request.getSession(Request.java:2097)
    at org.apache.catalina.connector.RequestFacade.getSession(RequestFacade.java:833)
    at org.springframework.web.servlet.support.DefaultFlashMapManager.retrieveFlashMaps(DefaultFlashMapManager.java:149)
    at org.springframework.web.servlet.support.DefaultFlashMapManager.requestCompleted(DefaultFlashMapManager.java:202)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:830)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)

这就是我的请求处理程序的样子

@RequestMapping(value = "/foo", method = RequestMethod.POST)
public String getFoo(RedirectAttributes attr) {
  attr.addFlashAttribute("twiddle", "doodle");
  return "redirect:/cow";
}

有谁知道导致此问题的原因/如何调试问题？

Answer 1

经过一番调查，发现提供发布到/foo 的表单的 JSP View 具有 session=false 页面指令属性，如下所示:

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"  session="false" %>

Spring 重定向属性使用 HttpSession 对象，该属性会导致跳过 HttpSession 生成。删除该属性/将其设置为 true 后，重定向工作正常